The present invention relates to electronic organs wherein the solo manual is multiplexed, and in particular to a system for generating fill notes wherein scanning or multiplexing of the accompaniment manual is not necessary.
Present-day electronic organs include keyboards which are either of the single manual variety, as in the case of spinet organs, or plural manual variety, as in the case of larger console or theater organs. In the case of a single manual organ, the keys on the right portion of the keyboard corresponding to the higher frequency notes are customarily played by the right hand of the performer, and the keys on the left portion of the keyboard corresponding to the lower frequency notes are customarily played by the left hand. In two manual organs, wherein each manual may be a full sixty-one note manual or, alternatively, two forty-four note manuals which are offset relative to each other, the upper manual is generally played by the right hand and the lower manual by the left hand. The upper manual and the right hand portion of the spinet keyboard are generally referred to as the solo manual, and the lower manual and left hand portion of the spinet keyboard are generally referred to as the accompaniment manual.
In playing such an instrument, chords are generally formed by depressing the appropriate keys on the accompaniment manual, and the melody is generally played on the solo manual. The melody may be played monophonically or polyphonically, depending on the skill of the performer. The fullness of the sound produced by playing the organ can be greatly enhanced if chords harmonically compatible with the chords played on the accompaniment manual are also played on the solo manual together with the melody note or notes. Although the full chord may not be played, it is customary to play one or two notes of the chord, known as fill notes. This technique requires a high degree of skill, however, particularly in view of the fact that the fill notes must be held as other melody notes are played.
In order to enable beginning and intermediate players to achieve the same fullness of sound achieved by more advanced players who are capable of playing the fill notes, systems have been developed for generating fill notes of this nature automatically by mechanically or electronically coupling signals resulting from playing keys on the accompaniment manual to the tone producing circuitry such that the notes will sound as if they were played on the solo manual, preferably within an octave or two of the highest note which is played on the solo manual. The following patents are exemplary of prior art systems for automatically generating fill notes in electronic organs: U.S. Pat. Nos. 3,283,056; 3,745,225; 3,823,246; 3,247,310; 3,990,339; 3,929,051; and 4,112,802.
The disadvantage to the earlier fill note generation systems, such as those disclosed in U.S. Pat. Nos. 3,283,056 and 3,823,246 is that they require cumbersome mechanical or electronic interconnection of the key switches. Although this problem was alleviated by systems such as those of U.S. Pat. Nos. 3,990,339 and 4,112,802, they are more suited to automatic chord systems wherein the chord information is developed by the depression of a single key in the accompaniment manual. U.S. Pat. No. 3,929,051 discloses a system which is usable in the alternative configuration, wherein the chords must be manually played on the accompaniment manual to generate the fill note information. In this system, however, the accompaniment keys, or at least interconnected groups thereof, are scanned by the drivers which also scan the keys of the solo manual. This results in a restrictive system and the interconnection circuitry is quite unwieldy.